Luminescent materials emit light when exposed to certain radiation, such as electron radiation. Certain luminescent materials are useful as phosphors in video displays. For example, cathode ray tubes and field emission displays function by having a layer of phosphor-comprising material applied on an internal surface of a face or display plate. Radiant energy impinged upon the face plate causes the phosphors to luminesce. Color displays typically include three different types of phosphors, namely red, green and blue (RGB), which, when excited in various combinations, produce colors for presentation through the face of the display. The phosphor-comprising material is typically oriented or arranged in a series of discrete areas comprising one type of phosphor, and are referred to as pixels.
Field emission display (FED) technology continues to be developed with an intent to replace the relatively bulky cathode ray tubes of the past. FED devices typically comprise a microtip structure comprising tiny conical electron emitters. The emitters are made as small as possible, with hundreds of them being utilized to illuminate a single pixel. Certain field emission display applications achieve high electron density, which in the context of this document is defined as anything greater than or equal to 1 microamp/cm.sup.2 of electrons. Many existing phosphor materials are not particularly stable or operate satisfactorily at such electron densities.
Accordingly, there is a continuing need to develop different or improved phosphors.